As an example of current practice in an automobile dealership, there may be a large number of vehicles, each of which has its own individual key or keys. Certain of the salesmen may be assigned certain of the cars or trucks to which they can have access for sale or demonstration. Others may be permitted to deal with all of the vehicles except a chosen few high priced or specified units which may have their own specialized salesmen. The manager, and sometimes certain other designated people, will be allowed access to all vehicles.
Typically all the keys may merely be hung up in order on a board, sometimes, but not always, supervised by a senior or other member of the establishment responsible for security. Depending on the number of keys involved, such as boards can occupy a considerable surface area. The search for one particular key can waste a great deal of time, as can the accurate refiling of the keys, quite apart from not infrequent loss by the users. These inconveniences are very hard to control when there are many users and keys.